The present invention concerns apparatus for cleaning fabrics, garments and the like in liquid carbon dioxide, which apparatus includes a rotating basket.
Numerous different apparatus for washing garments and fabrics are known. Examples of patents on washing machines include U.S. Pat. No. 1,358,168 to McCutchen, U.S. Pat. No. 1,455,378 to Allen, U.S. Pat. No. 2,357,909 to Ridge, U.S. Pat. No. 2,816,429 to Kurlancheek, and U.S. Pat. No. 3,444,710 to Gaugler. Such apparatus is, in general, adapted to home use with water-based cleaning systems.
Non-aqueous cleaning apparatus, known as xe2x80x9cdry cleaningxe2x80x9d apparatus, is also known. Dry cleaning employs an organic solvent such as perchloroethylene in place of an aqueous system. Dry cleaning apparatus is not, in general, employed in the home, and is instead situated at a store or central plant. Problems with convention dry-cleaning systems include the toxic nature of the solvents employed.
Carbon dioxide has been suggested as a dry cleaning medium. See, e.g., U.S. Pat. No. 4,012,194 to Maffei. To date, however, a feasible apparatus for carrying out carbon dioxide cleaning has not been provided. One apparatus is described in U.S. Pat. No. 5,467,492 to Chao et al. This apparatus has apparently been supplanted by the apparatus described in U.S. Pat. No. 5,669,251 to Townsend et al. Townsend describes a dry cleaning system having a hydraulically rotated basket that rests on roller bearings. The system is adapted to use with liquid carbon dioxide. Manifolds are disposed between an outer pressure vessel and the basket and have nozzles that produce jets of liquid carbon dioxide that agitate the garments. The basket is said to be rotated by the friction of the garments against the basket walls (column 4, lines 47-48) or by a paddle wheel or turbine (col. 5, lines 8-9). A disadvantage of Townsend is that the basket is supported by roller bearings around the periphery of the basket, which are complex and prevent simple removal of the basket for cleaning, inspection, etc. A further disadvantage of Townsend is that roller bearings are required between the basket side wall and the side wall of the pressure vessel. Since roller bearings are relatively large, this increases the xe2x80x9cdead spacexe2x80x9d between the side wall of the basket and the side wall of the pressure vessel, which dead space must be filled with liquid that is not operating to clean clothing within the basket.
U.S. Pat. No. 5,267,455 to Dewees et al. describes a dry cleaning system in which carbon dioxide as a cleaning medium is transferred between vessels by means of a second purge gas such as nitrogen. The use of multiple pressurized gases makes the system considerably more complex. The system employs a rotating basket, but a disadvantage is that the basket is rotated by means of a magnet coupling. Magnetic couplings provide an inefficient drive means for a rotating basket.
U.S. Pat. No. 5,850,747 to Roberts and Kegler describes a liquified gas dry-cleaning system with a pressure vessel temperature compensating compressor. No means of driving a basket within the vessel is suggested.
A cleaning apparatus adapted for use with a carbon dioxide cleaning medium comprises a body member, a door connected to the body member and together with the body member forming a pressure vessel, and a basket disposed within the body member. The basket is supported with a rotating shaft. A motor is contained within, rather than outside, the pressure vessel, and a drive mechanism is also contained within the pressure vessel for rotating the basket with the motor. Because the motor and drive mechanism are both contained within the pressure vessel, the need for a rotating shaft that penetrates the pressure vessel, and which must be sealed at least in part against the high pressure liquid contained therein, is obviated.
More particularly, an apparatus of the invention comprises:
a body member having a front opening formed therein, the body member having side walls and a back wall opposite the front opening, the side walls terminating in a front body member edge portion defining the front opening;
a door connected to the body member, the door having a front wall and side walls, with the side walls terminating in an inner edge portion configured to abut the body member edge portion; the body member and the door together forming an enclosed pressure vessel;
a substantially cylindrical basket disposed within the body member for rotation about a generally horizontal axis, the basket having a front opening formed therein, the basket having a side wall and a back wall opposite the front opening, the side wall terminating in a front basket edge portion defining the basket front opening;
an elongate shaft connected to the basket back wall and coincident with the axis, and
a shaft support connected to the body member back wall, with the shaft disposed in the shaft support to permit rotation of the basket within the body member without the shaft penetrating through the back wall;
a motor contained within the pressure vessel; and
a drive mechanism interconnecting the motor to the elongate shaft and configured to rotate the basket.
The foregoing and other objects and aspects of the present invention are explained in the drawings herein and the specification set forth below.